The harness is currently reporting 78 tests from RC4 as invalid:
http://test.csswg.org/harness/results?s=CSS21_%HTML_RC4&f=23
This means that these tests were reported as invalid (from a formal
implementation report by a vendor) in previous versions of the test
suite and have not been changed since that report.
I accept that it's possible that some of these tests have been
examined and found to be valid after all, if that's the case, I need a
list of those so I can clear the invalid state. If they're genuinely
invalid, then these are the tests that need fixing first for RC5...
Peter